Comparative evaluation of 11 essential oils of different origin as functional antioxidants, antiradicals and antimicrobials in foods

This study was conducted to identify and evaluate the antimicrobial activity of some Lactobacillus isolates of chicken origin. Among 90 isolates 14 Lactobacillus species were distinguished using MALDI-TOF mass spectrometry and 16S-ARDRA. The dominant species was L. salivarius (34.4%), followed by L. johnsonii (23.3%), L. crispatus (13.3%) and L. reuteri (11.1%). All lactobacilli were screened for antimicrobial activity against wild-type strains of Salmonella enterica, Escherichia coli, and Clostridium perfringens. Results from the agar slab method showed that all Lactobacillus isolates were able to produce active compounds on solid media with antagonistic properties against these pathogens. The highest sensitivity to lactobacilli was observed in C. perfringens strains, and the lowest in E. coli. Lactobacillus salivarius exhibited particularly strong antagonism towards all of the indicator bacteria. Strains of L. ingluviei and L. johnsonii and one strain of L. salivarius (10d) selectively inhibited the growth of C. perfringens. No antimicrobial activity of many Lactobacillus isolates was observed when cell-free culture supernatant was used in a well diffusion assay. All Lactobacillus isolates exhibited the ability to produce H2O2 and proved to be hydrophobic (excluding one of L. salivarius). [Int Microbiol 19(1):57-67 (2016)]Keywords: Lactobacillus spp. · avian lactobacilli · antimicrobial activity · gut health · poultry pathogens

Antimicrobial activity of

Monkeypox is a zoonotic disease caused by monkeypox virus (MPXV), which is a member of orthopoxvirus genus. The reemergence of MPXV in 2017 (at Bayelsa state) after 39 years of no reported case in Nigeria, and the export of travelers’ monkeypox (MPX) from Nigeria to other parts of the world, in 2018 and 2019, respectively, have raised concern that MPXV may have emerged to occupy the ecological and immunological niche vacated by smallpox virus. This review X-rays the current state of knowledge pertaining the infection biology, epidemiology, and evolution of MPXV in Nigeria and worldwide, especially with regard to the human, cellular, and viral factors that modulate the virus transmission dynamics, infection, and its maintenance in nature. This paper also elucidates the role of recombination, gene loss and gene gain in MPXV evolution, chronicles the role of signaling in MPXV infection, and reviews the current therapeutic options available for the treatment and prevention of MPX. Additionally, genome-wide phylogenetic analysis was undertaken, and we show that MPXV isolates from recent 2017 outbreak in Nigeria were monophyletic with the isolate exported to Israel from Nigeria but do not share the most recent common ancestor with isolates obtained from earlier outbreaks, in 1971 and 1978, respectively. Finally, the review highlighted gaps in knowledge particularly the non-identification of a definitive reservoir host animal for MPXV and proposed future research endeavors to address the unresolved questions.

Monkeypox Virus in Nigeria: Infection Biology, Epidemiology, and Evolution.

The use of medicinal plants as immunostimulants in aquaculture: A review

Virus infection of mammalian cells is sensed by pattern recognition receptors and leads to an innate immune response that restricts virus replication and induces adaptive immunity. In response, viruses have evolved many countermeasures that enable them to replicate and be transmitted to new hosts, despite the host innate immune response. Poxviruses, such as vaccinia virus (VACV), have large DNA genomes and encode many proteins that are dedicated to host immune evasion. Some of these proteins are secreted from the infected cell, where they bind and neutralize complement factors, interferons, cytokines and chemokines. Other VACV proteins function inside cells to inhibit apoptosis or signalling pathways that lead to the production of interferons and pro-inflammatory cytokines and chemokines. In this review, these VACV immunomodulatory proteins are described and the potential to create more immunogenic VACV strains by manipulation of the gene encoding these proteins is discussed.

Vaccinia virus immune evasion: mechanisms, virulence and immunogenicity

Evaluation of extracts of the root of Landolphia owerrience for antibacterial activity

Aqueous extracts of the leaf of Harungana madagascariensis were analysed phytochemically and evaluated for antimicrobial activity against strains of Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa. Glycosides, tannins, saponins, flavonoids and alkaloids were detected in the plant material. B. subtilis, E. coli and S. typhi, but not Ps. aeruginosa, showed susceptibility at MICs of 2.0 and 15.6 mg/mL; and MBCs of 2.0-3.9 mg/mL and 15.6-31.3 mg/mL, respectively, for the cold and hot extracts. Staph. aureus showed susceptibility only to the hot extract. Concentrations of 2.5-10.0 mg/mL of the cold extract killed over 7 log(10) of the test bacterial population within 30-60 min of exposure. The hot extract needed higher concentrations and longer treatment to achieve similar levels of bacterial cell killing. The results provide a rationalization for the traditional use of H. madagascariensis leaf extracts for the treatment of gastrointestinal disorders.

Antibacterial activity of Harungana madagascariensis leaf extracts.

The ongoing monkeypox outbreak in non-endemic countries is likely to be a consequence of the failure to curtail the spread of the disease in endemic regions of Africa despite decades of constant outbreaks. A globally driven one health approach to prevention and treatment of the disease is essential to control present and future outbreaks. 

/pdf/monkeypox-virus-a-neglected-zoonotic-pathogen-spreads-2ppz3axw.pdf

Monkeypox virus: a neglected zoonotic pathogen spreads globally

Recombinant viruses based on modified vaccinia virus Ankara (MVA) are vaccine candidates against infectious diseases and cancers. Presently, multiplication of MVA has been demonstrated in chicken embryo fibroblast and baby hamster kidney (BHK-21) cells only. The multiplication and morphogenesis of a recombinant (MVA-HANP) and non-recombinant MVA strain in BHK-21 and 12 other mammalian cell lines have now been compared. Rat IEC-6 cells were fully permissive to MVA infection. The virus yield in IEC-6 cells was similar to that obtained in BHK-21 cells at low as well as high multiplicities of infection. Vero cells were semi-permissive to MVA infection. Mature virions were produced in supposedly non-permissive cell lines. The multiplication and morphogenesis of non-recombinant MVA and MVA-HANP were similar. These results are relevant to the production and biosafety of MVA-vectored vaccines.

Malachy Ifeanyi Okeke

Papers

Monkeypox Virus in Nigeria: Infection Biology, Epidemiology, and Evolution.

Evaluation of extracts of the root of Landolphia owerrience for antibacterial activity

Antibacterial activity of Harungana madagascariensis leaf extracts.

Monkeypox virus: a neglected zoonotic pathogen spreads globally

Modified vaccinia virus Ankara multiplies in rat IEC-6 cells and limited production of mature virions occurs in other mammalian cell lines.